A conventional transformer is disclosed, for example, in DE 297 14 253 U, where the conductor piece forms the primary conductor and the secondary winding surrounds the conductor piece in the form of a ring and are embedded in an insulating material body. The planar contact face and the plug-in contact piece are guided out of the insulating material body in order to be able to electrically connect the planar contact face, for example, to an electrical busbar and the plug-in contact piece, for example, to a power breaker. Within such a bushing-type transformer, the conductor run of the primary conductor is bent at right angles and is then bent back. The kinks form sites where there is increased electrical resistance and which are heated to a greater extent and these sites must be taken into account in the overall design of the bushing-type transformer.